Got to the overworld quest, went and explored the mountain and cave, grabbed the brown wool...and now I'm stuck, as I can't find my way home.
After the frustration that was Ice Castle and Reds, I think I'm done with this pack.
As for constructive criticism: I feel like the level design got lazier the further into the pack I went. This is further reinforced by the fact that later levels have far less objectives. It went from levels providing a challenge but being adequately rewarding (Biosphere is a great example of this) to just areas with loads of spawners and not many chests. Sure, the 2 or 3 chests an area would have would contain legendary bags, but once you have flying and some decent armor (not to mention a legendary bag farm), those chests are honestly pretty lackluster. The maps stopped being fun around Miner's Delight^4. That was the first map that just felt like it was designed to kill me without regard for actual enjoyment. Rotunda^4 wasn't actually that bad, although Ice Castle and Reds are most definitely the largest offenders in the 'kill players, no rewards' category.
Ice Castle is just 'hey, lets see what I can do with ice blocks and creepers', with lackluster rewards at best. Reds needs to be scrapped. A solid block of Silverfish Eggs is not only anti-fun, but can be hell on servers if your players decide to get creative (I decided TNT would be the most efficient way to find the wool. One server crash later, I was mining by hand). If you're insisting on keeping Reds the way it is, at least make a stone path down to the wool itself, so players can manually feel out the path with their pickaxe, instead of having to mine an egg, kill some silverfish, and repeat, hoping they find the skystone box.
Lastly, the Overworld. It's a neat concept, and the Dwarven Fortress was really nice. The problem is not everyone is going to bring stacks upon stacks upon stacks of torches with them. I myself had Night Vision via Ender IO and Flying, so I just flew where I needed to go. I proceeded to lose my spawn point, as I didn't think to note down the coordinates; I assumed (wrongly) that there would be a method of exit at the wool.
Furthermore, the way back into The End seems to be bugged, unless flying is mandatory at this point, as jumping into the end portal to what I assumed was home just left me on a platform in the end, with nothing in sight. After flying around aimlessly for a while I found the portal and the dragon egg that took me back into the facility, but had I not had flying, I would have been stuck there, short of killing myself (which, if the design is intended this way, needs to be changed).
I agree with a substantial portion of this having obtained the "hypercubed" wools just last night. Ice Castle wasn't terrible, just stupidly annoying (I might be biased as I had a silk touch hammer that had Knockback on it on me at the time, but whatever). Reds was a giant fricking piece of nope. I got lucky as I managed to find the, as I call it, "Space-Time Fleecy Box" relatively quickly. The only reason I
might go back there is just to harvest the AE2 stuff there, and even then...
Fortunately, I saw your post before I did the whole Overworld quest part, so I sort of knew what to expect going in, but even so. Using the Deep Dark as a way to move between the End and the Overworld is finicky at best. On that topic, I wholeheartedly agree with you on the Overworld: Great concept, but it needs work (and maybe some hints to bring torches in the quest book itself).
As for the way back into the End being bugged... Not really. On the platform below the egg's chamber, there's a piece of bedrock with some white lights (Can't remember if they're the XU Lapis Caeleastris blocks, or if they're just Chisel Anti-Blocks), if you put a button on the bedrock and press it, you'll be teleported back to the Reflection Pool chamber. When I found it, it already had a button there, so again, another issue that needs to be remedied as it's highly doubtful that the player will carry buttons around with them.
As for one thing that pissed me the hell off, personally, no idea about other players, was that stupid gauntlet run in the Nether to get the brown wool... It just felt super unimaginative and almost designed to absolutely annihilate players that have weaker computers and/or were badly prepared. I mean, really, 32(?) Wither Spawners in a row and a spawner starts operating once a player gets within a 16-block radius of one and if you're standing on one, another one or two are well within range. That's three Withers the player has to deal with at once. The only good thing is that the Withers might blow up the spawners for you, but that tends to be luck of the draw. I know enough AFTER the fact that I should've looked into Tartarite weapons (and armour) for dealing with Withers, but even so...
Most complaints aside, I do have to sing this pack's praises for how well done the first half of the gameplay is. There are a few points where the gameplay is finicky, but I can handle that. My only big wish is that there were some additional storage options outside of wooden chests, Sky Stone Chests, Caches and the Strongboxes in the Observatory. I would say to add Jabba to the pack, but Parcel would probably counter with the TE Caches and I see why. It's pretty easy to get your mitts on Tin right from the get-go, they're "easy" to upgrade (which I half-agree on; upgrading Jabba tiers is simple, but storage capacity isn't), and it's easier to move Caches around. One thing that Jabba has over Caches is that you can just walk by and see how much of something is in the barrel, you need (as far as I know) to pick a Cache up to actually see how much is in it.
I do have one recommendation though: Add most inventories to the Holoinventory config blacklist. While useful to find those annoying-to-find EIO Item Buffers and seeing if item processing is finished, it very quickly gets overwhelming if you have a fairly dense physical storage area like I do, at least up until I can get AE2 working.
Yeah... That's my two cents worth on this. Don't get me wrong, I do enjoy the pack and, like anything else, it just needs refinement and some additional tweaks. Now, if you'll excuse me, I have the rest of the trophies to locate and to explore the community spatial areas.